Feed throwout mechanism for sewing machines



June 22, 1954 R, L, HQFFMEls-y-ER 2,681,628

FEED THROWOUT MECHANISM FOR SEWING MACHINES Filed April l5, 1955 2Sheets-Sheet l INVENTOR. l gert oe. gfolnez'ser ATToRNEY N w a 3@ lI.........H I .w n w T S J o m ....\.|rr|| fra.

WITNESS June 22, 1954 `Filed April 15.

R. L. HGH-MEISTER 2,681,628

` FEED THROWOUT MECHANISM FOR SEWING MACHINES 2 Sheets-Sheet 2 ATTURNEYl Patented June 22, 1954 FEED THROWOUT MECHANISM FOR SEWING MACHINESRobert L. Hoffmeister, Helensburgh, Scotland,

assignor to The Singer Manufacturing Company, Elizabeth, N. J., acorporation of New Jersey Application April 15, 1953, Serial No. 348,897

Claims.

The present invention relates to sewing machines and has for a primaryobject to provide a new and improved feed throw-out mechanism for asewing machine.

More specically, it is an object of the present invention to provide anew and improved feed throw-out mechanism which is of simplifiedconstruction and thus more economical, and one which is more readilyaccessible and easier to operate so that it may be more convenientlyactuated to effect feed throw-in or throw-out. Further, itis an objectof this invention to provide a feed throw-out mechanism which iseiiicient and thoroughly dependable in operation.

Having in mind the above and other objects that will be evident from anunderstanding of this disclosure, the invention comprises the devices,combinations and arrangements of parts as illustrated in the presentlypreferred embodiment of the invention which is hereinafter set forth insuch detail as to enable those skilled in the art readily to understandthe function, operation, construction and advantages of it when read inconjunction with the accompanying drawings in which:

Fig. 1 is a bottom plan view of a sewing machine in which a throw-outmechanism in accordance with the present invention has been incorporatedin the feed-lift mechanism.

Fig. 2 is a fragmentary section view taken substantially on the line 2-2of Fig. 1.

Fig. 3 is a fragmentary section view taken substantially on the line 3 3of Fig. 1.

Fig. 4 is a section view taken substantially on the line 4-4 of Fig. 1.

Fig. 5 is a fragmentary section view similar to Fig. 2 but with thefeed-drive in throw-out position and with parts broken away toillustrate more clearly the mechanism lying behind the same.

, The present invention is illustrated as embodied in a sewing machinesimilar to that disclosed in the patent of Eames, No. 2,024,434, andhaving a bed I provided with the usual throat plate 2. Journaledlongitudinally of the bed I in suitable lugs 3 and 4 depending from thebed is a rotary shaft 5. At one end the shaft 5 carries a pulley 6 aboutwhich is entrained a belt '1. Although not illustrated, the belt 'I maybe driven from a belt pulley fixed to the usual bracket-arm shaft which,in turn, may be driven by a beltdriven pulley as illustrated in theabove Eames patent. Thus rotation is delivered to the shaft 5.

The end of the shaft 5 opposite to that end carrying the pulley 6 isfitted into a bore formed in a loop-taker housing 8 and is journaled ina suitable bushing 8a provided in the lug 3 and extending into thehousing 8. The housing 3 is provided with a laterally extending flange 9(Fig. l) that is secured to the under side of the bed I by a screw I0,which, together with the bushing 8a, constitutes the sole support forthe housing 8. A horizontal transverse bore is provided in the housing8, in which bore there is journaled the loop-taker shaft II having aloop-taker in the form of a rotary hook I2 xed to one end thereof.Within the housing 8, the shaft II has: secured thereto a gear I3 thatmeshes with a gear I 4 fixed to the end of the shaft5. In the usualmanner the ratio between the gears I3 and I4 is 2:1 whereby theloop-taker shaft I I will be driven at twice the speed of the shaft 5.The gears I3 and I4 may be lubricated by packing the interior of thegear-housing 8 with grease. The open side of the gear-housing is closedby a plate I5.

As hereinbefore mentioned, the gear-housing 8 is supported solely by thebushing 8a and the screw I 0, which arrangement simplifies the assemblyof a machine incorporating the same. With this construction, it ispossible to completely assemble the hook-shaft II and its gear I3,together with the hook I2 and other elements within the housing 8 as asub-assembly, then position the same in place with the shaft 5 Withinthe provided bore, and nally secure the same .in place by the screw I0and fixing the gear I4 to the end of the shaft 5. This constructionfacilitates manufacture as well as assembly since it makes it possibleto drill the appropriate bores in the housing 8 by working on theeasier-to-handle housing by itself rather than on the machine bed Iwhich would be the case if the bores were formed in appropriate lugsdepending from the bed.

The feed in the disclosed embodiment of the invention includes afeed-advance mechanism substantially as illustrated in the above patentof Eames to which reference may be had for a full description thereof.Briey, the feed-advance mechanism includes a rock-shaft IB journaledlongitudinally of the bed I in suitable depending lugs I'f and I8.Oscillation is imparted to the rock-shaft I 6 by a bar I9 that isconnected thereto by a crank 20 (Fig. l). The opposite end of the bar I9pivotally and adjustably receives a rod 2| that is carried by a frame 22secured to a countershaft 23 journaled in lugs 24 depending from the bedI. The frame 22 includes a fork 25 that embraces an eccentric 26 on theshaft 5.

- bore It@ is provided in the ange du.

rIhus, as the shaft 5 rotates, oscillation about the countershaft 23 isimparted to the frame 22, which through the rod 2l, bar I9 and crank 20,oscillates feed-shaft I6. The bar I9 may be moved relative to the rod 2I, as by the actuation of a link 21 connected to the bar at anintermediate point, in order to vary the amount of reciprocation of thebar I9 and thus to vary the oscillation of the shaft I6.

At its opposite end, the shaft I6 carries aI feedroclier Z, between theopposed arms of which is pivotally mounted one end of a feed-bar 29. Theother end of the feed-bar 2li-carries the feed-dog Sil which operatesthrough the usual slots Si in the throat-plate 2 to contact the work andto move the same past the stitching mechanism of the machine.V

Feed-lift movements are imparted tothe feeddog by an oscillatingcrank-arm 32 having a sliding block 33 tted between the arrns of a fork:trl that is formed as an integral portion of the feed-bar 29. Thecrank-arm 32 is secured tc a feed-lift shaft or countershaft 35journaled longitudinally of the bed` I in depending lugs lever or pitman3l is loosely mounted at one end on the countershaft 35l and at theother end formed with al fork 33 that embraces an eccentric 39 on theshaft 5. The pitinan 3l is provided with a transverse flange fillintermediate its ends. A collar II is fixed to the countershaft 35adjacent the pitman 3l which collar is provided with an arm t2 thatunderlies the ange it on the pitman 3T. An enlarged bore i3 is formed inthe arm 4E' and an axially alined threaded A thumbscrew L35 having ahead I6 passes loosely through the bore d3 and is threaded into the borelili.

When the thumb-screw is screwed into the bore dll, thehead llt is drawnagainst the arm of the collar which` is forced into engagement with theflange du on the pitrnan 3l and thus secured thereto as illustrated inFig. 2. When so connected, the collar ill, which is secured to thecountershaft 35, is coupled to the pitman and thus the pitman is coupledto the countershaft 351 Upon rotation of the shaft 5, the eccentric i9will effect an oscillation of the pitman 3l, which oscillation will beimparted to the countershaft through the flange 40, thumb-screw l5 andcollar 4I. Oscillation of the countershaft 35 will impart feed-liftmotions to the feed-dog t@ through the crank 3'2 and feed-bar 2S.

When the thumb-screw :l5 is backed-off as il.- lustrated in Fig. 5,v theconnection between the iiange 49 and the arm 42 of collar I I, and,hence, the connection between the pitman 3l and the countershaft 35 isbroken. In this condition, the pitman 3l will oscillate freely relativeto the countershaft and will not impart its oscillation thereto, thescrew 45 reciprocating freely within enlarged bore of the arm 42. Toinsure that the feed-dog is retracted from its work-engaging positionwhen the feed-lift mechanism is thrown out, there is provided a torsionspring lil' fitted within a counterbore of the collar iti, which springsurroundsA the'countershaft 35 and has its opposite ends embedded in thepitman 3l and the collar 4I as seen in Fig. 3. The spring lll istsnsioned to bias the collar 4I and thus the countershaft in thatdirection in which the feeddog is urged downwardly from its operativeposition, or in a clockwise direction as viewed in Figs. 2 and 5.Downward movement of the feeddog is limited by a stop-screw 1S threadedthrough a flange-I9 of the loop-taker housing 8 fili which screw is inposition to contact the feed-bar as it is urged downwardly by the spring4l.

Numerous alterations of the structure herein disclosed will suggestthemselves to those skilled in the art. However, it is to be understoodthat the present disclosure relates to a preferred embodiment of' myinvention which is for purposes of illustration only and not to beconstrued as a limitation of the invention. All such inodications whichdo not depart fromthe spirit of the invention are intended to beincluded within the scope of the appended claims.

Having thus set forth the nature of the invention, what I claim hereinis:

l. In a feedingV mechanism for a sewing machine, a feed-lift shaft, asource of oscillation, and disconnectible means for operativelyconnecting said feed-lift shaft to said source of oscillation comprisinga lever loosely pivoted coaxially of said feed-lift shaft andoperatively connected to said source ofv oscillation, a flange on saidlever, a collar fixed to said feed-lift shaft, an arm onV said collardisposed adjacent to said flange, said flange and said arm havingsubstantially axially aligned bores therein with theaxes thereofarranged substantially parallel to the plane of oscillation of saidlever, threads formed in a rst one of said bores, and a shoulderedthreaded element extending loosely through the outer of said bores andoperatively engaging the threads in said first one of said bores fordisconnectibly coupling said lever to said arm.

2. In a feeding mechanism for a sewing machine, an actuatingl shaft, afeed-lift countershaft arranged substantially parallel to said actuatingshaft and disconnectible means for operatively connecting saidcountershaft to said actuating shaft for oscillation of the former uponactuation of the latter, comprising, an actuating element fixed to saidactuating shaft, a pitrnan freely pivoted coaxially of said countershaftand operatively engaging said actuating element' to be oscillatedthereby, a flange on said pitman, a collar fixed to said countershaft,an arm on said collar disposed adjacent to said flange, said flangeV andsaid armv having substantiallyI axially aligned bores therein with theaxes thereof-'arranged substantially parallel'to the plane ofoscillation of said pitlnan, threads formed in a first one of saidbores, and shouldered threaded element extending loosely through theother of said bores and operatively engaging the threads in said firstone ofv said bores for disconnectibly coupling said pitman to said arm.

3. In a feeding mechanism for a sewing machine, a feed-lift shaft, asource of oscillation, and disconnectible means for operativelyoonnecting said feed-lift shaft to said source of oscillation,comprising, a lever loosely pivoted coaxially of said feed-lift shaftand operatively connected to said source of oscillation, a ange on saidlever, a collar fixed toisaid countershaft, an arm on said' collardisposed adjacent to said fia-nge, said ange and saidarm havingsubstantially axially aligned bores therein with the axes thereofarranged substantially parallel to the plane of oscillation of saidlever, threads formed in a rst one-of said bores, a shouldered threadedelement extending loosely through the other of said bores andoperatively engaging the threads in said rst one ofV said bores fordisconnectibly coupling said lever to said arm, andV resilient means forbiasing said arm away from said il'ange.

4. In a sewing machine, an actuating shaft, a

counter-shaftl arranged substantially parallel' to said actuating shaft,a feed-bar, a crank secured to said oountershaft and operativelyconnected to said feed-bar for imparting feed-lift movements theretoupon oscillation of said countershaft and said crank, disconnectiblemeans for operatively connecting said oountershaft to said actuatingshaft for oscillation of the former upon actuation of the latter,comprising, an actuating element xed to said actuating shaft, a pitmanfreely pivoted coaxially of said countershaft and operatively engagingsaid actuating element to be oscillated thereby, a flange on saidpitrnan, a collar fixed to said countershaft, an arm on said collardisposed adjacent to said flange, said iiange and said arm havingsubstantially axially aligned bores therein with the axes thereofarranged sulostantially parallel to the plane of oscillation of saidpitman, threads formed in a first one of said bores, and a shoulderedthreaded element extending loosely through the other of said bores andoperatively engaging the threads in said first one of said bores fordisconnectibly coupling said flange to said arm.

5. In a sewing machine having a bed, a rotary hook-actuating shaftjournaled longitudinally of said bed, a feed-lift countershaft journaledlongitudinally of said bed and arranged substantially parallel to saidhook-actuating shaft, a feed-bar, a crank secured to said countershaftand operatively connected to said feed-bar for imparting feed-liftmovements thereto upon oscillation of said countershaft and said crank,disconnectible means for operatively connecting said countershaft tosaid hook-shaft for oscillation of the former upon rotation of thelatter comprising an actuating element xed to said hook-actuating shaft,a pitman freely pivoted coaxially of said countershaft and operativelyengaging said actuating element to be oseillated thereby, a flange onsaid pitman, a collar fixed References Cited in the le of this patentUNITED STATES PATENTS Number Name Date 1,879,190 Gooseman Sept. 27, 19321,879,191 Gooseman Sept. 27, 1932 1,908,292 Grieb May 9, 1933 2,440,031Wainwright Apr. 20, 1948 2,652,797 Amman Sept. 22, 1953

